No Catalytic Converters
 

Hey 370z tuners, I have some questions about tuning. First, when I bought my car, the previous owner had removed the catalytic converters and put Z1 test pipes on the car (I live in the part of Virginia where we don't have emissions tests). Since I have gotten the car, I have put cold air intakes and AAM resonated short tails on the car. So I was looking to get a tune. I have never had a car tuned before, so this was going to be my first experience with the whole thing. I contacted a tuner, and set up an appointment and told them about my setup. They said they could do it. Today they call and say they can't tune a car without catalytic converters because of their policy, and offered to install some for about $1200 or give me a refund. I took the refund.

So my questions are:
Can a car be tuned without catalytic converters?
Am I ruining my car by not having them?
Does anyone know a good tuner on the central East Coast that would tune a car without cats?
If I do get cats, which ones should I get to make the most power?

Thanks!

Smart move on the refund. Most tuners are happy to tune your cat-less car with a disclaimer that the tune is meant for off-road use only. Sounds like someone doesn't want your money lol

Thanks JAR, great info! I appreciate your time and answers!

To follow up with what Jar has stated.

The tuners he recommends are very good. If you're technology competant, you could also reach out to Sebastian from Specialty Z. He does remote tunes. You essentially plug your laptop into the OBD port and collect a data log for him. He tweaks the log and sends it back to you with instructions on what he wants to see. Rinse and repeat a few times. Wala, you have a tuned car.

Jars recommendations on fast intentions pipes are highly respected. Very solid handcrafted work from a very reputable place. Only downdraw is they usually have a decent wait time on fabrication.

Personally, i'd go with HFC's over TP's, but that's just due to the loudness and smell they can give off. Totally your call though. Neither will hurt your car in any way. You may just feel the car is acting sluggish until a tune is done. The ECU's for our cars is very robust at keeping up with bolt-on mods.

Thank you, Leingod! I am not overly confident in my technical skills where car tuning is concerned. I think I would rather take it somewhere and pay a professional for a day. I like your recommendations, thank you for your time!

It is because of the EPA. I suspect more tuners to go this route in the future. The harder the hammer falls the worse it will get.

It is a violation of Federal and state law to remove your catalytic converter. Therefore, my guess is the tuner could be fined under VA law for tuning your car.

I'm not sure if it's a legal thing or not. I can't find any statewide laws for Virginia regarding them except that the inspection book says that if they are repaired they may be welded to the exhaust pipe. I bought my car from Carmax, and took it to the dealer to have it looked over. The dealer told me about my exhaust set up, and I asked if it was going to be a problem with the law or passing inspection, and they said, "No." They passed it this past winter, so it seems like they weren't lying (about passing inspection anyway).

I have a very loud exhaust, and have never been pulled over for it. In fact, I think recently Virginia banned cops from pulling people over for exhaust, tint, lights out, etc. :vuvuzela:

So maybe the law is on my side? Probably not, though.

Either way, I'm looking to get it tuned. I guess sooner rather than later, from the sounds of it.

https://19january2017snapshot.epa.go...hsysrepair.pdf

https://law.lis.virginia.gov/adminco...70/section300/

I had not seen that EPA file before, and it does state you can't remove the cats. The VA law does not say if you can or not.

Just because you don't live in an inspection state doesn't mean you can remove the cats. In Florida you can receive a $2000 fine for doing so!

Agreed, plus,

Federal law supersedes state law every time.

EPA reg states all vehicles built after (iirc) 1968 must have cats if they came with them oe.

Again, iirc, the FEDERAL fine for violating this is around $37k per offense. The EPA has been known to have vans parked along the highways that are equipped with “sniffers” that can get you when/if you drive by. Odds are good that probably won’t happen but it’s out there. Also, any LEO can pull you over in any state if they smell that “catless” odor as probable cause and a quick visual inspection could mean a state level fine but possibly even a federal one depending on your luck.

Long story short, IMO it’s not worth the risk for a street driven car to go catless. ESP when there are federal EPA compliant hfc’s out there. No hfc will meet CARB, but some will meet federal regs. I don’t know if fast intentions hfc fall into that category or not, but they are one of the best companies out there for high quality z parts.

You can go catless until you get caught.

Just want to add one more thing, I was just perusing the latest EPA reg update from December 2020. They reiterated that epa compliant cats are ok, but they’ve tightened regs on OBD tampering. In other words, only afaik carb approved tuning is epa compliant regardless of hfc used.

Example, APR has apr plus carb approved stage 1 tines for many vehicles. Edelbrock has carb approved s/c for Jeeps that includes a locked carb compliant tune. I’m not sure anything like this exists for the 370z.

This is good motivation to pick up a z35 since it’s tt from factory and carb approved stage 1 tuning is pretty easy to get for turbo cars.

Well, I think I'm going to look into getting HFCs, just to be compliant and whatnot. Plus it will probably help resale if I ever sell my car. They should also reduce the rasp in my exhaust tone.

So Fast Intentions is the way to go? The only other exhaust mod I have is AAM Resonated Short Tales. Anyone have this axleback and have an HFC they like?

If you have the cash and don't mind the wait time, FI is definately the way to go. I've been running the rhfcs for years without a single issue. I ran them initially with stm short tails. They're now paired with FIs full exhaust. With the short tails, it was loud, but maneagable. You will piss off your neighbors in the morning. With a full exhaust, you can have a conversation in the cabin without yelling.

I leave before most of my neighbors wake up, so I'm sure most of them don't even set alarm clocks because the just consider my cold start all the alarm they need.

It would be nice to have a conversation once in a while I guess, but getting rid of the rasp is my main concern. I actually put a different axleback on my car 2 days ago that had bigger resonators on it, but the cold start was just as loud. The cruising drone was less though. I like the way the AAM Short Tales look and sound better, though, so I switched back.

If I go with Fast Intentions, should I get the High Flow Cats (HFCs) or the Resonated High Flow Cats (RHFCs). I see on their website they only have the RHFCs for sale, but I heard the used to make non-resonate ones. I'm sure I could find some if I look hard enough.

Well FL has no testing sites and no emission requirements for registration....I'm going to do whatever the fuq I want to my car until that changes. Cops don't care at all down here from what I've seen. Never been pulled over and I've had cops sit behind me for like 5 minutes in traffic and I know they could smell my car....because all the prius drivers give me dirty looks. :rofl2:

The FED is corrupt as all hell anyway from top to bottom, I don't give a shiz about their mandates or Orwellian 1984 rules.
"Rules for thee, but not for me"...pfft shove it.

Those who sell or install devices to defeat emission controls can be fined over $4,800 per defeat device, and dealers can be fined over $48,000 per tampered vehicle. In 2019 one diesel performance shop was fined over a million dollars. Though its very rare that anyone actually gets fined ever, a disgruntled costumer can make threats and scare a shop to just stop doing it for awhile.

It has happened to several folks in the Diesel industry. That crap started back in 2007 when particulate filters were introduced. I can remember a couple of companies that went out of business.

If you are quite about it, you probably won't have any issues. If you are disrespectful, loud, and obnoxious like above, The the EPA will rain hell down on all of us.

Gov starts over stepping its bounds and becomes too authoritarian, freedom loving patriots get loud about it usually.

Steve Dinan was on The Smoking Tire Podcast and he was saying that you don't need to remove the cats!

Unless referring to a racing application, no one should be arguing there is a need to remove the cats. Of course there's no need. There are pros and cons to removing them. Each person's end goal and level of risk aversion is going to determine whether removing the cats is the right decision for them.

Personally, I think test pipes are too loud for certain types of street driving. But I like the smell of gas, so I chose to live with the noise.

My HFC + motodyne combo is honestly perfect. It's hardly loud when driving normally, but it will make noises when i get on the loud pedal. Combined with running E85, hardly any smell.

I hate the smell of raw fuel. E85 makes it so much better. It burns so much cleaner too.

No need to remove them but if your car is boosted there would be a need to move them downstream more. My mil spec cats are in the lead pipes

Interesting, I'm the opposite, I can't stand the smell of gas. My old 350, that I bought used, had the cats removed and the smell of gas really got to me sometimes. My current car has resonated HFCs and it's a bit louder than I would prefer but I'm used to it. And, it wasn't worth the cost of new cats to swap them out...lol.

You guys don't know what real gas smells like. Back before the 80's. You could get 98 octane from the local gas station pump. And every car didn't have cats on it. Every heavy truck rolled coal. 2 stroke motorcycles mixed with bean oil. That's a smell that you will never forget. :tup:

I wish cars burned the castor oil. Loved the smell of Klotz

Nothing better than the smell of race gas. Ethanol stinks like wet socks. Nasty smelling.

Something like this?

Smells like mash whiskey :eek: